Papillary carcinoma within a thyroglossal duct cyst: significance of a central solid component on ultrasound imaging.

Malignancy within a thyroglossal duct cyst is rare (1.5% of cases), and most diagnoses are made postoperatively as clinically they are difficult to distinguish from benign neoplasms. We present a case in which a preoperative ultrasound scan showed the presence of a central solid component in a thyroglossal duct cyst, which contained papillary thyroid carcinoma.